1. Technical Field
Example embodiments of the present invention generally relate to an image forming apparatus, an optical writing device, and/or a housing molding method providing a simple structure, e.g., for preventing a light leakage.
2. Description of Background Art
A background image forming apparatus, for example, a copying machine, a printer, a facsimile machine, or a multifunction printer having copying, printing, scanning, and facsimile functions, forms a toner image on a recording medium (e.g., a sheet). In the image forming apparatus, an optical writing device scans a light beam onto an electrostatic latent image carrier (e.g., a photoconductor) according to image data to form an electrostatic latent image on the photoconductor. The electrostatic latent image is developed with a developer (e.g., a toner) to form a toner image. The toner image is transferred onto a sheet. Thus, the toner image is formed on the sheet.
One example of a background optical writing device includes a light source, a polygon mirror, a polygon motor, an image forming lens, a light receiver, a sensor, and/or a housing. The light source emits a light beam toward the polygon mirror. The polygon motor drives the polygon mirror. The rotating polygon mirror deflects the light beam toward the image forming lens. The image forming lens focuses the light beam to scan on the surface of the photoconductor to form an electrostatic latent image on the surface of the photoconductor. To form an electrostatic latent image on a valid area on the surface of the photoconductor, a writing start position or a writing end position is adjusted in a main scanning direction. For example, the light receiver receives a light beam irradiating an invalid area outside the valid area on the surface of the photoconductor in the main scanning direction. The sensor outputs a detection signal determining a writing start position in the main scanning direction. The housing contains the light source, the polygon mirror, the polygon motor, and the image forming lens.
The background optical writing device further includes a collimate lens and/or an aperture. The collimate lens collimates a light beam emitted by the light source. The aperture adjusts the collimated light beam into a reference shape.
A light beam entering the collimate lens from an enter plane of the collimate lens may be reflected by an inner wall of an exit plane of the collimate lens, and may be further reflected by an inner wall of the enter plane of the collimate lens before emerging from the exit plane of the collimate lens. The light beam may not irradiate the aperture but may irradiate an opening formed between the collimate lens and the aperture. Thus, the light beam may leak from the opening. Further, a light beam emitted by the light source is diffused before being collected by the collimate lens. The diffused light beam may also leak from an opening formed in the optical writing device.
When the leaked light beam (e.g., a flare light beam) enters the image forming lens, the light beam may reach the surface of the photoconductor via a reflecting lens. As a result, a faulty image having a jitter, a background jitter, and/or an uneven color density may be formed. When the light receiver receives the flare light beam, the sensor may erroneously detect the light beam. As a result, an electrostatic latent image may not be properly formed on the valid area on the surface of the photoconductor.